The U.S. Food and Drug Administration (FDA) has granted approval to Guardant Health's Shield blood test for colorectal cancer (CRC) screening in adults 45 years and older. This decision marks a significant advancement in CRC detection, offering a convenient alternative to traditional screening methods and potentially increasing screening rates among the unscreened population.
Shield, which has been available as a laboratory-developed test (LDT) since 2022 at a self-pay price of $895, detects CRC through a blood sample. The FDA's approval moves Shield closer to Medicare coverage eligibility, potentially eliminating out-of-pocket costs for beneficiaries aged 65 and older.
Clinical Performance and Comparison
According to FDA documents, a study of Shield demonstrated an 83% sensitivity for detecting colorectal cancer. While this is lower than the 92.3% sensitivity reported for Exact Sciences' stool-based test, Cologuard, blood-based tests offer a less invasive and more convenient option for many individuals. Colonoscopy remains the gold standard for CRC screening and diagnosis.
Impact on Screening Rates
Leerink Partners analyst Puneet Souda estimates that the FDA's decision could help target more than 50 million unscreened individuals. The convenience of a blood test may encourage higher participation rates, leading to earlier detection and improved outcomes. The FDA approval is the second for a blood-based test for CRC screening in the United States after Epigenomics’ Epi proColon, which was approved in 2016 but failed to meet the government’s 74% or more sensitivity criterion for Medicare coverage.
Colorectal Cancer Burden
CRC is a significant public health concern, affecting approximately 150,000 Americans annually and causing over 50,000 deaths each year, according to the FDA. Increased screening rates are crucial for early detection and reducing mortality associated with this disease.
